Which of the following is the structural material that composes the natural nail?

• A. Keratin
• B. Collagen
• C. Chitin
• D. Fibroblast

Answer: (A)

The natural nail is primarily composed of keratin, which is a type of protein. Keratin is a key structural component not only of nails but also of hair and the outer layer of skin. Its unique properties provide strength and resilience to the nail, allowing it to protect the underlying tissues.

Collagen, although important in the overall structure and health of skin and connective tissues, does not primarily compose the nail itself. Chitin is a structural component found in the exoskeletons of arthropods and certain fungi, and while it shares some similarities with keratin, it is not found in human nails. Fibroblasts are cells that contribute to the formation of collagen and connective tissues but are not a structural material themselves. Therefore, keratin is the correct answer, accurately reflecting the composition of natural nails.